At present, a clapping type electromagnetic tripping system of a molded case circuit breaker in which an electromagnetic field is generated on an iron core using a short-circuited current flowing through a heating element and an armature is attracted to push a tripping rod to make a product disconnected ensures the safety of a power supply system; and this clapping type electromagnetic tripping system mainly comprises an iron core, an armature, a heating element, a thermal bimetallic element, a bracket, a supporting member, a flexible wire and a connecting plate. The heating element penetrates through a magnetic loop composed of the armature and the iron core, and a magnetic field will be generated on the iron core surrounding the heating element when the short-circuited current flows through the heating element; and if the generated magnetic field force is not sufficient to attract the armature, short-circuit protection fails, and in particular, in a clapping type electromagnetic tripping system of a specification of 63 A or less.